Don’t prune anything now – especially spring bloomers

WASHINGTON – Judy in Arlington writes: “I thought I heard you say something recently on ‘TOP about pruning, but I missed most of it. Is this a good time to shape bushes such as forsythia, laurel, azaleas and others? They look unkempt but are alive and well despite the heat.”

No, Judy — this is the worst time of year to prune anything. You’ll stimulate new growth and interfere with the plants successfully going dormant for the winter, which might make next summer their last summer. And it’s a doubly bad time to think about pruning forsythia, azaleas and other spring bloomers. Their buds are already set for next season. Pruning them now would remove all the potential flowers and destroy your chances of a springtime show.

Prune spring bloomers right after they finish flowering in the spring. Prune summer bloomers as soon as they show new growth in the spring. And if you’re unsure of when to prune, don’t prune!

But you can deadhead

Kevin in Leesburg writes: “I have a Crape Myrtle tree that is loaded with buds that don’t appear to be flowering anymore — I presume because it’s so late in the season. Should I do anything with the buds — like cut them off? The branches are bent quite a bit from the weight. Any other tips you could pass along would be appreciated as I have planted another one recently.”

Well, the best advice would normally be to leave it alone and follow the correct crepe myrtle pruning advice, which is to cut each branch back by a foot or so in the spring. But big heavy buds like the ones you describe could cause winter problems, so I’ll give you permission to deadhead the ends. That means just cut off those flower buds. Don’t prune the branches back or you’ll stimulate new growth at the worst time of year. And in normal years, just prune the trees back by a foot or so every spring.

This “deadheading” advice holds true for pretty much any plant that flowers late in the season. You may remove the faded flowers and unopened buds in the fall. For instance, I’ll go out after our first hard freeze and remove the very tips of my raspberry canes, where the late crop of berries was produced. It’s good for the plants and makes things look much more tidy. But just take off the very tips of any plants that recently flowered. Don’t do more than deadhead them. And leave all your other plants alone.

We got a lot of response to a recent post in which I explained that the Virginia Supreme Court had ruled that homeowners can be held liable for damages when invasive plants like bamboo do harm to a neighboring property. “I have a ‘bamboo neighbor,'” wrote Vic in Montgomery County. “Can you provide a reference or citation for that decision?”

My pleasure, Vic. The case is Fancher v. Fagella, and the opinion was issued on Sept. 14, 2007. It states when “encroaching trees and plants cause actual harm or pose an imminent danger of actual harm to adjoining property, the owner of the tree or plant may be held responsible for harm caused to the adjoining property.” In other words, if your bamboo uproots my driveway, you have to get rid of the bamboo and repair the damages.

An even more concrete case against bamboo

Jeff in Chevy Chase writes: “I heard your piece on property damage caused by bamboo and thought I’d share how my dad and I handled the situation. We dug a 2- foot deep trench along the edge of our property next to the neighbor’s stand of bamboo and filled it with concrete. The bamboo has never gotten underneath it (or otherwise crossed into our property) in the 15 years since. It was a solution that required a fair amount of work, but was extremely effective.”

Well, you’ve proven once again that good fences make good neighbors, Jeff, even if the fence in question is below ground. Professional landscapers use a specially- made material known as rhizome barrier in much the same manner to try and keep aggressive and destructive plants like the notorious running bamboo contained, but it appears that you and your dad did the pros one better.

Feed fescue now — not zoysia

Donna from Stafford writes: “Is it OK to feed zoysia grass with corn gluten meal? My front lawn is zoysia, and the back is mostly zoysia, with some remaining fescue that we want the zoysia to choke out. I wanted to put corn gluten down to help control some of the weeds, but was wondering if it might negatively affect our zoysia grass.”

Your suspicions are correct, Donna. This is the time of year to feed cool season grasses, like fescue, rye and bluegrass, not warm-season grasses like zoysia or Bermuda. The warm season grasses that many in our region are warming up to because they survive summer so much better are going dormant now, and you should never feed a plant that’s trying to go dormant.

And feeding that mixed lawn of yours now would help the fescue as it harms the zoysia — exactly the opposite of what you want to achieve. So if you want that warm-season grass to take over, don’t feed your turf now. Instead, be ready to feed it with corn gluten as soon as the zoysia begins to green up again in the spring.

And the same goes for allayouse out there: Feed cool-season grasses now and in the early spring; warm-season grasses mid-spring through summer.